The present invention relates to methods for removing antiplatelet agents and anticoagulants from a platelet preparation. In one embodiment, the method includes the step of flowing the platelet preparation through a filtering tube comprising a filtering membrane and separating the antiplatelet agents and anticoagulants from the platelet preparation by tangential flow filtration. In another embodiment, the method includes the step of passing the platelet preparation through porous material that specifically binds to the antiplatelet agents and anticoagulants.